This invention relates to sliding doors or other such closure assemblies, and more particularly to an insert for the support track of a sliding closure assembly.
It is now commonplace to employ bypass doors for a wide variety of applications, including door, window, and cabinet closures. Bypass doors are often commonly referred to as sliding closure assemblies or sliding doors, even though the supporting mechanism most often employs wheels.
While various designs and combinations of sliding closures are currently used, including single or multiple track sliding fixtures, virtually all sliding closure designs incorporate at least one sliding element or door that functions to close an opening when in the proper position. All sliding closures require some type of support for the sliding door elements that they incorporate. Numerous methods of support for such doors are well known in the art, such as the bottom-supported assembly disclosed in U.S. Pat. No. 4,262,451 to Dallaire, the top-supported hanging assembly disclosed in U.S. Pat. No. 3,750,337 to Brydolf, et al, the side-supported assemblies disclosed in U.S. Pat. No. 2,218,149 to Haynes, U.S. Pat. No. 2,064,830 to Hanson, and U.S. Pat. No. 3,167,112 to Tucker, or a combination of such supports as disclosed in U.S. Pat. No. 4,819,297 to Jacobs, et al, and U.S. Pat. No. 4,193,500 to Scott. These assemblies all incorporate at least one wheel assembly which travels in a support track, supporting the weight of the sliding door. As the door travels along the support track, rotation of the wheel in the wheel assembly minimizes frictional forces in the system, allowing smooth and unimpeded movement of the door.
Because it is desirous for the operator of a sliding closure to be able to easily move the doors, top and bottom support sliding closures are typically constructed to minimize frictional forces opposing motion along the support track. This allows the operator to easily move the door to a desired location with a minimum of effort. For these types of supports, it is most desirable that the support track be at or near a level plane (essentially horizontal). When properly constructed, any horizontal forces acting on the door resulting from gravitational attraction will be minimized, allowing the frictional forces inherent in the support system for the door to overcome such minimal horizontal forces, thus maintaining the door in its resting position absent operator intervention.
However, where there is poor construction, settling of a building and/or movement/warpage of the sliding closure or the door frame, it may be difficult to keep a door in its fully closed position. Also, in some situations it may be desirable to maintain a door in a particular closed or open position. For example, in triple bypass doors, it is difficult to maintain a middle door in a central position relative to the doors on each side.
It is possible to provide locking devices that mechanically engage the support structure to "lock" the door in a desired position, such as disclosed in U.S. Pat. No. 4,478,006 to Johnson and U.S. Pat. No. 2,064,830 to Hanson. However, these devices require the operator to disengage the mechanical "lock" prior to moving the door, reducing the convenience and desirability of such a closure. Such mechanical locking devices are also readily visible, and thus detract from the appearance of the sliding closure, often a critical feature in the commercial success of a given design. In addition, the incorporation of such a locking device into an existing sliding closure would likely require substantial alteration of the underlying support structure, at attendant additional expense.
Therefore, there is a need in the art for a device to maintain a closure in a selected positions, while still allowing substantially free, unimpeded movement of the door during normal operation. Such device should not be readily visible to the casual observer, so as to not detract from the appearance of the sliding closure assembly, and it should be easy to install in existing facilities.